WASHINGTON (CNN) -- The man who revealed that Valerie Plame worked for the CIA said that he was "extraordinarily foolish" to leak her name.
Former Deputy Secretary of State Richard Armitage was a source of the CIA leak to columnist Robert Novak.
Former Deputy Secretary of State Richard Armitage told CNN's Wolf Blitzer in an interview broadcast Sunday that he did not realize Plame was a covert agent when he discussed her with syndicated columnist Robert Novak.
Novak, a former CNN contributor, wrote the July 2003 column in which Plame was named as a CIA employee. He later cited his sources as Armitage and Karl Rove, then President Bush's top political adviser.
"There was no ill intent on my part, and I had never seen, ever in 43 years of having a security clearance, a covert operative's name in a memo," he said. Watch Armitage explain why he leaked Plame's name »
Blitzer asked Armitage if he "simply assumed that she was not a clandestine officer of the CIA."
"Well, even Mr. Novak has said that he used the word 'operative' and misused it," Armitage said. "No one ever said 'operative.' And I not only assumed it, as I say, I have never seen a covert agent's name in a memo. However, that doesn't take away from what Mrs. Plame said. It was foolish, yes."
Rove, who left the White House in August, has denied he was also a source of the leak to Novak.
Plame's identity was disclosed shortly after her husband, former U.S. Ambassador Joseph Wilson, challenged one of the chief claims underpinning the Bush administration's case for the U.S. invasion of Iraq -- that Iraq had sought uranium for nuclear weapons from the African country of Niger.
In an op-ed piece for The New York Times, Wilson wrote that he had investigated the claim at the request of CIA officials and found it "highly doubtful" that any such transaction could have occurred, and he accused the Bush administration of having "twisted" the evidence for war.
Neither Armitage nor Rove was charged with a crime in the leak.
Wilson and Plame have accused Rove and other Bush officials of leaking her identity as a CIA officer in retaliation for her husband's emergence as an administration critic.
A federal judge in Washington recently dismissed a lawsuit by the couple against Rove, Armitage, Vice President Dick Cheney and Cheney's former chief of staff, Lewis "Scooter" Libby.
Libby was convicted of obstructing justice and perjury in the probe and sentenced to 30 months in prison, but Bush commuted his term before he had served any time. E-mail to a friend